An image sensor (an infrared sensor) having sensitivity in an infrared region has been commercialized recently. In a light-receiving element used in this infrared sensor, a photoelectric conversion layer including a group III-V semiconductor, such as indium gallium arsenide (InGaAs), is used, and infrared rays are absorbed on the photoelectric conversion layer, thereby electric charges are generated (photoelectric conversion is performed). Various proposals on an element structure of such a light-receiving element or an imaging device have been made (for example, PTL 1).